ROS opencv

sudo apt-get install ros-noetic-opencv*
sudo apt-get install ros-noetic-usb-cam
sudo apt-get install ros-noetic-cv-bridge
sudo apt-get install ros-noetic-cv-camera

cd ~/catkin_ws/src
catkin_create_pkg ros_opencv message_generation cv_bridge image_transform sensor_msgs roscpp serial std_msgs

 

package.xml

CMake:Lists.txt

 

//ros_opencv_pub

#include <cv_bridge/cv_bridge.h>

#include <opencv2/opencv.hpp>

#include <image_transport/image_transport.h>

#include <iostream>

#include <vector>

#include <ros/ros.h>

#include <opencv2/highgui/highgui.hpp>

#include <std_msgs/UInt8MultiArray.h>

int main(int argc, char** argv)

{

ros::init(argc, argv, "opencv_pub");

 

ros::NodeHandle nh;

ros::Publisher pub = nh.advertise<std_msgs::UInt8MultiArray>("camera/image", 1);

cv::VideoCapture cap(0);

cv::Mat frame;

 

while(nh.ok())

{

cap >> frame;

if(!frame.empty())

{

cv::imshow("frame", frame);

// Encode, Decode image example

std::vector<uchar> encode;

std::vector<int> encode_param;

 

encode_param.push_back(cv::IMWRITE_JPEG_QUALITY);

encode_param.push_back(20);

 

cv::imencode(".jpg", frame, encode, encode_param);

cv::Mat decode = cv::imdecode(encode, 1);

cv::imshow("decode", decode);

// Convert encoded image to ROS std_msgs format

std_msgs::UInt8MultiArray msgArray;

msgArray.data.clear();

msgArray.data.resize(encode.size());

std::copy(encode.begin(), encode.end(), msgArray.data.begin());

// Publish msg

pub.publish(msgArray);

cv::waitKey(1);

 

}

ros::spinOnce();

}

return 0;

 

}

 

//ros_opencv_sub

#include <ros/ros.h>

#include <opencv2/opencv.hpp>

#include <image_transport/image_transport.h>

#include <opencv2/highgui/highgui.hpp>

#include <cv_bridge/cv_bridge.h>

#include <vector>

#include <std_msgs/UInt8MultiArray.h>

void imageCallback(const std_msgs::UInt8MultiArray::ConstPtr& array)

{

try

{

cv::Mat frame = cv::imdecode(array->data, 1);

cv::imshow("view", frame);

cv::waitKey(1);

}

catch (cv_bridge::Exception& e)

{

ROS_ERROR("cannot decode image");

}

}

int main(int argc, char **argv)

{

ros::init(argc, argv, "opencv_sub");

cv::namedWindow("view");

cv::startWindowThread();

ros::NodeHandle nh;

ros::Subscriber sub = nh.subscribe("camera/image", 5, imageCallback);

ros::spin();

cv::destroyWindow("view");

}